Traffic pollution at the home address and pregnancy outcomes in Stockholm, Sweden

Abstract

BackgroundFor the past two decades, several studies have reported associations between elevated levels of ambient air pollution and adverse pregnancy outcomes, although with varying conclusions.ObjectivesTo examine possible associations between the traffic pollution situation at the home address, for women who did not change address during pregnancy, and three types of pregnancy outcomes: spontaneous preterm delivery, children born small for gestational age (SGA) and pregnancy-induced hypertensive disorders.MethodsWe used data for the Greater Stockholm Area from the Swedish Medical Birth Register to construct a cohort based on all pregnancies conceived between July 1997 and March 2006, n=100 190. The pregnancy average nitrogen oxide, NOx, levels and annual mean daily vehicles at the home address were used as exposure variables. Mixed-model logistic regression was performed to assess any associations between exposure and outcome.ResultsThere was an association between elevated traffic pollution exposure during pregnancy and pregnancy-induced hypertensive disorders. A 10 µg/m3 increase in the pregnancy average NOx level at the home address resulted in an OR of 1.17 (95% CI 1.10 to 1.26). The 2nd to 4th quartiles of NOx were all associated with an increased risk of SGA, but there was no difference in the risk estimate among the higher quartiles. There was a tendency of a higher risk of spontaneous preterm delivery in relation to higher levels of NOx. There was no evidence of an association between vehicle flow, the cruder indicator of traffic pollution, and the studied outcomes in this study.ConclusionsIn this large cohort, there was a fairly strong association between vehicle exhaust levels at the home address and pregnancy-induced hypertensive disorders, after adjustment for important risk factors.

Residential proximity to traffic and female pubertal development

“…Both short and long-term traffic-related air pollution (TRAP) exposure has been associated with adverse health effects, particularly for vulnerable populations such as pregnant women and children (McConnell et al, 2015; Olsson et al, 2015). Children are more vulnerable to the effects of air pollution because they breathe more air per unit of body weight than adults (Arcus-Arth and Blaisdell, 2007) and spend more time outdoors (Bateson and Schwartz, 2008).…”

NTP Monograph on the Systematic Review of Traffic-related Air Pollution and Hypertensive Disorders of Pregnancy

“…Nine studies were identified that evaluated associations between traffic-related NO2 or NOx exposures and preeclampsia or combined hypertensive disorders of pregnancy. The available evidence included five retrospective cohort studies from Spain ), Sweden (Olsson et al 2015), the United States ) and Australia ; three prospective cohort studies from Denmark ), Norway (Madsen et al 2018), and The Netherlands (van den Hooven et al 2011); and one casecontrol study from Sweden ). The number of participants in these studies ranged from 7,000 to more than 260,000 pregnant women and included between 100 and 17,000 cases.…”

“…The number of participants in these studies ranged from 7,000 to more than 260,000 pregnant women and included between 100 and 17,000 cases. All studies assessed traffic-related NO2 or NOx exposures using LUR models Madsen et al 2018; or air dispersion models Olsson et al 2015; , , and reported median (IQR) levels of NO2 and NOx. b Blood pressure case sample size reflects the number of women who had blood pressure measurements taken.…”

“…Slight negative associations were reported between exposure to relatively low levels of NO2 during the full gestational period and preeclampsia and gestational hypertension (Madsen et al 2018) and between first and second trimester NO2 exposures and hypertensive disorders of pregnancy (after adjusting for the delivery hospital ]). NO2 or NOx exposures that were estimated using air dispersion models were between 10.7 and 16.7 µg/m 3 for most studies Olsson et al 2015;), but the highest concentration (40 µg/m 3 ) was reported by van den Hooven et al (2011). Estimates of NO2 concentrations using LUR models ranged from 43.3-55.7 µg/m 3 .…”

Exposition aux gaz d’échappement diesel durant la gestation : quelles conséquences sur le développement foeto-placentaire ? Apport des modèles animaux

“…Un lien a été observé entre l'augmentation des concentrations en NO et NO 2 et l'apparition de l'un des symptômes de PE (hypertension artérielle) chez la femme enceinte (Olsson et al 2015). De plus, une augmentation de la concentration en oxydes d'azote dans l'air environnant la femme enceinte est associée à une réduction, chez le nouveau-né, de la concentration plasmatique en vitamine D, impliquée dans de nombreux processus cellulaires et métaboliques dont le métabolisme des os et du calcium (Baiz et al 2012).…”